Device for applying back pressure to forgings in drawbench passes



NOV. 23, 1943. I LE RQY LAYTQN 2,335,154

DEVICE FOR APPLYING BACK PRESSURE T0 FORGINGS IN DRAW BENCH PASSES Filed"June-r4, 1942 5 Sheds-Sheet l NOV. 23, 1943.- LE R Y LAYTQN' I2,335,154

DEVICE FOR APPLYING BACK PRESSURE TO FORGINGS IN DRAW BENCH PASSES FiledJune 4. 1942 5 Sheets-Sheet 5 Nov. 23, 1943. LE ROY LAYTON 2,335,154

DEVICE FOR-APPLYING BACK PRESSURE TO FORGINGS IN DRAW BENCH PASSES FiledJune 4, 1942 5 Sheets-Sheet 4 -36 Z}' 7j0 I I 'Fy' -7 V 6 F da 66'I/III/IIII/ 1 I.

I Even/Z 5} lefi lygy 71/ 01 173 J W! Nov. 23, 1943.

LE ROY LAYTON Filed June 4, 1942 DEVICE FOR APPLYING BACK PRESSURE TQFOEGINGS IN D RAW BENCH PASSES 5 Sheets -Sheet 5 Patented Nov. 23, 1943DEVICE FOR APPLYING BACK PRESSURE TO FORGINGS IN DRAWBENCH PASSES Le RoyLayton, Lansdowne, Pa., assignor to Lansdowne Steel & Iron Company,Morton, Pa., a corporation of Pennsylvania Application June4, 1942,Serial No.; 445,798

14 Claims.

This invention relates to a method and apparatus for improving theinterior surfaces of the bottoms of the powder chambers ofexplosiveshell forgings.

The method and apparatus of the present :invention are particularlyadaptablefor use in conjunction with the method and apparatusforfinishing forgings disclosed in my prior U. S. Letters Patent No.2,248,002, dated July 1, 1941, andNo. 2,278,325, dated March 31, 1942.The present invention, howevenis also applicable to other forms of theso called draw benches employed in the manufacture of hollow forgings ofvarious kinds.

The external bottom surface of .a shell forging occupies a plane atright angles to the coinciding longitudinal axes of the cylindricallbodyof the forging and thev axial cavity which constitutes the powderchamber thereof; and the internal bottom of the powderchamber is usuallyof a concentric parabolicor other tapering form.

The parabolic bottom of the powder chamber is usually formed overa'mandrel which is forced into the primary piercing of theforging,where-.-

by this piercing eventually constitutes the pew der chamber. 1

By axial movement of the mandrel, the forging is advanced throughsingleor multiple ring or roll passes having throats of progressivelydecreasing diameters respectively. The: diameter of each threat is, tosome slight degree at least, smaller than the outside diameter of theforging, whereby the metal of the forgin is radially condensed orcompacted and stretched or formed over the paraboloidal nose and axiallycontiguous circular shank of th mandrel, which causes the internalparabolic surfaceof the bottom andthe axially contiguous cylindricalboreof the powder chamber to conform to the external surfaces of saidparaba-loidal nose andcorrespondingly axial contiguous circular shankofthe mandrel, to shape and accurately dimension the interior of thepowder chamber.

The piercing tool, which. forms the primary piercing in the forging intowhich the'mandrelis subsequently projected in normal course'of usage,becomes pocked or grooved by abrasion, and when withdrawn from apiercing leaves small protuberances or ridges projecting from theinternal surface of the piercing into the interior cavity thereof.

When the paraboloidal nose of the mandrel is inserted in the primarypiercing, it engages the high spots of the protuberance's and ridges,which prevents the entire area of the internal surface of the bottom ofthe 1 powder chamber cavity from making complete over-all contact withthe whole of the external. surface of the nose of the mandrel.

If .a ring, pass. is, employed inqthe finishing process and the diameterof the throat thereof is sufficiently smaller than the outsidewdiameterof the forging. to apply enough resistance to the advancingof theforging through saidthroatby said mandrel to flatten out the aforesaidprotuberances, ridges, etc., the external bottom surface of the forgingis frequently bulged fromits normal flat planar condition and insomeline stances is actually perforatedby the..nose of the mandrel,under the forcerequired to advancethe forging through the throatof theringdie.

If a roll pass is employed for finishing the forging, the possibilitiesof the bulging or perforating of the exterior bottom of the forging arepractically eliminated, however, the protuberances remain within thepowder chamber and prevent proper contact of the inner surface thereofwith the nose of the mandrel.

If the throat of the roll passis excessively, decreased to applysufficient resistance to the forward motion of the forging to eifectflattening of the protuberances by the nose of the mandrel, theparabolic bottom ofthe' powder chamber is frequently squeezed away from.and elongated-in front of the paraboloidal nose of the mandrel, as theportion of the forging lying in the crosssectional plane of 'or adjacentthe extremity of the nose passes-throughthe bite of the rolls of, saidpass, leaving a space between the nose of the mandrel and the bottomsurface of 'thepowder chamber whichdistorts said chamber.

The principal object of the present invention is to eliminate each andall of'the aforesaid disadvantages of the finishing processesnow beingemployed. f 1

Another. object of. the invention. is to flatten out all of the.objactionable,protuberances, ridges, etc,- on the, interior surfacesofthe powder chambers of the forgings, without bulging or perforating theshell bottoms- V 7 Another object of the inventionis to provide a fiatfaced anvilfagainst which the exterior bottom surface of the shellforgings bear as said forgings are forced through the throats of. the

' ringorroll passes during, the finishing of the interior surfaces of,their powder chambers, whereby axial bulging or perforating .oftheshellbottoms are prevented.

Another object of the inventionisto provide means for applying apredeterminedbackpressure or. resistance against the normally fiatexternal bottom surface of a forging, through the aforesaid anvil, tothe advancing movement of the shell forging through thering orroll pass,in opposition to .the power applied to the mandrel for effecting saidadvancing of the shell forging.

Anotherobject of the invention is to. provide means. for controllingtheback pressure applied by the anvil, and for releasing said" backpresthe mandrel has advanced through the ring or roll pass.

' Another object of the invention is to provide means for projecting theback pressure anvil through the throat of a secondary ring or roll passto the plane of initial contact of the bottom end of the shell forgingwith the rolls or ring forming the throat of an initial ringor rollpass.

The construction and operation of the mechanism of the presentinvention, in conjunction with the finishing mechanism disclosed in theaforesaid prior U. S. Letters Patent, willbe fully disclosedhereinafter, reference being had to the accompanying drawings, of which:

Fig. 1 is a side elevation of the apparatus of the present inventioncoupled, intandem, to the apparatus of the aforesaid Letters Patent;

Fig. 2 is an enlarged longitudinal vertical sectional elevationdisclosing the back pressure mechanism in its resistance-affordingposition;

Fig. 3 is a viewcorresponding to Fig. 2 but showing theresistance-affording mechanism in its effective position;

Fig. 4 is a transverse sectional elevation taken on the line 4-4, Fig.1;

Fig. 5 is a transverse sectional elevation taken on the line 5-5, Fig.1;

Fig. 6 is a transverse sectional elevation taken on the line 6--6, Fig.1;

Fig. '7 is a transverse sectional elevation taken on the line 1-1, Fig.1;

Fig. 8 is a transverse sectional elevation taken on the line 8-'-8, Fig.1;

Fig. 9 is a sectional plan view taken on the line 9-9, Fig. 1;

Fig. 10 is an end view as seen from the plane and direction indicated bythe arrow-bearing line lD-Ifl, Fig. 1;

Fig. 11 is a longitudinal sectional elevation of a shell forgingshowingprotuberances in the powder chamber left by a pocked and scoredprimary piercing tool; and

Fig. 12 is a view similar to Fig. 11, but showing the irregularities inthe wall of the powder chamber after being eradicated by use of themethod and apparatus of the present invention.

As disclosed in the two aforementioned prior patents, and as shown inFig. 1 of the present case, a hot primary forging 13 which has beenpierced to form the powder chamber thereof, is placed in a horizontallydisposed trough 9, with the longitudinal axis of the forging coaxiallyaligned with the longitudinal axis of the finishing tool or mandrel l0.7

The pre-formed piercing'C is slightly greater, cross-sectionally, thanthe mandrel III, at substantially all corresponding cross-sectionalplanes of the mandrel and the forging. a

The mandrel I is advanced axially into the cavity C of the primaryforming B freely and without making any substantial contact with theinterior walls of the cavity, until the extreme outer end ll of themandrel comes into contact with the extreme inner bottom end 0 of thecavity C Continued axial movement of the mandrel If! advances theforging B into the bite of a series of rolls R R having concaveperipheral faces which collectively constitute the throat of a first orprelimary pass, concentric to the longi- V tudinal axis of thehorizontally movable mandrel Continued axial movement of the mandrel [0in the direction of the arrow a Fig. 1, forces the forging B through thefirst rolljpass, formed by the rolls R ,R. into and through the bite ofa series of rolls R R which collectively constitute the throat of asecond or finishing roll pass, concentric to the axis of the mandrelIll.

The throat of the first roll pass is of slightly smaller diameter thanthe outside diameter of the forging B consequently, as the forging isadvanced through the first roll pass, its outside diameter is reduced tothat of the pass, which effects a radial contraction and compacting ofthe metal of theforging around the outer surface of the mandrel l0,bringing the interior surface of V the powder chamber or cavity C intoclose intimate contact with the outer surface of the mandrel.

The diameter of the second roll pass is very slightly smaller than thediameter of the forging after it leaves the first roll pass and acts,primarily, to reduce any fine ridges that may have been formed on theouter surface of the forging by the abutting edges of the rolls of thefirst pass, it being noted that, as disclosed in the prior patents, therolls of the second pass are staggered to the extent of 90 degrees aboutthe axis of the mandrel with respect to the rolls of the first pass.

The external normally fiat bottom b of the forging B is formed in aplane x:r at right angles to the longitudinal axis yy of the forging.The bottom I) is provided with a pad b which extends outwardly beyondthe plane xr of the bottom I) and is of a smaller diameter than saidbottom.

According to the present invention, when the bottom plane :ca: of theforging B advances, in the direction of the arrow a Fig. 1, to the planeXX of the'bite of the rolls R1, R of the first pass, said forging bottom11 is engaged by a transverse flat face l2 of an anvil l5 which has beenconverselyadvanced in the direction of the arrow at? through the rollsR, R of the second 40 pass until the plane of the face l2 of the anvilcoincides with the plane X-X of the bite of the rolls R R of the firstpass;

The end face [2 of the anvil I5 is provided with a recess l3 into whichthe axial projection b of the forging 13 extends.

The mandrel IE] is advanced in the direction of the arrow oi under apredetermined hydraulic force of, for example, 90 tons per square inchpressure, which is opposed in the direction of the .arrow a by a backpressure of, for example, 40 tons per square inch pressure, applied tothe anvil l5. Consequently, as the nose of the mandrel l0 moves into thecavity C of the forging B and engages the high spots of anyprotuberances, ridges or other irregularities C (Fig. 11) on the innerparabolic bottom surface of the cavity 0, continued advance of themandrel In in the direction of the arrow a freely advances the forginginto the bite of the rolls R R Further advance of the forging B by themandrel l is then opposed by the mandrel l5.

The opposing force applied by the anvil i5 and distributed uniformlyover the entire area of the external bottom surface b momentarily, stopsthe forging B while the mandrel NJ continues to advance. Thus, anyprotuberances, ridges, or other irregularities encountered in the bottom0 of the cavity C are flattened out by the paraboloidal end ll of themandrel I0.

After flattening of any protuberances ,etc. encountered in the base 0 ofthecavity C the pressure exerted in the direction of the arrow (1 by themandrel l0 overcomes the pressure exerted in the direction of the arrowa? by the an vii I5, and the anvil I5 is caused to recede as a result ofthe greater advancing force supplied to the forging B by the mandrel lwhile'the opposing pressure exerted by the anvil is continued until thetapering or paraboloidical end of the mandrel l0, and thecorrespondingly shaped cavity C of the forging B from the end b to thecross-sectional plane az thereof have passed through the bite of therolls R R whereupon, the back pressure applied by the anvil |5 isreleased and nofurther resistance to the normal advance of the forging Bthrough the rolls R R and R R by the mandrel I0 is presented.

The forging B is advanced by the mandrel I8 until the rear or open end bof the forginghas passed through and beyond the housing |6 in which therolls R R are rotatably mounted, and beyond a stripper plate |8 which isslidably mounted in guides I1, I! on the rear end of the housing l6.After the forging B has passed completely beyond the stripper plate I8,said stripper plate is moved transversely into the path traversed by theforging, to form an abutment forthe end I) of the forging, after which,reversal of the direction of the movement of the mandrel lllcauses'therear end b of the forging B to engage the stripper plate l8, therebyforcing the forging off the mandrel I8 as said mandrel returns to itsnormal position beyond the front end trough 9, for the beginning ofanother cycle.

In the present instance, the anvil I5 is removably mounted onone end ofa horizontally operable ram 28. The anvil I5 is provided with a threadedaxial extension |5a which is screwed into a threaded cavity formed inone end of the ram 28.

The ram also includes a rearwardly extending cylindrical end 2|, of adiameter suitable for passage through the throat formed by the rolls R Rand a rectangular cross-head section 22 which is slidably mounted in alower guideway 23a and an upper guideway 23b.

The cylindrical section 2| of the ram 28 is interchangeably mounted onone end of the crosshead 22 by an axial threaded projection 21a screwedinto a correspondingly threaded bore in the-cross-head 22.

The rear end section 24 of the ram 20, like the anvil I5 is removablyconnected to said ram'by an axial threaded projection 24a screwed into acorrespondingly threaded bore in the rectangular cross-head 22 of theram2il.

The forward end face iii of the ram 26 is adapted to be engaged by aroller 25, which is rotatably mounted in a forked end of one arm of atriangular or bell crank lever 26. The bell crank lever 26 is pivctaliymounted on a shaft 21, between a pair of laterally spaced uprights 28,28. The second arm of the bell crank lever 26 is'forged and providedwith a roller 29 which is'engaged by the lower end of a verticallymoving plunger 38. The plunger 36 is slidably mounted in a verticalcylinder 3| having a base 32 which is secured to the upper endsofthe'uprights 28, 28, as by bolts 33.

Fluid pressure is admitted to the upper end of the cylinder 3| through apipe 34, from a source capable of producing a force of 40 tons persquare inch against the rear end I9 of the ram 28, through the bellcrank lever 26.

,Axially aligned with, and superposed on, the cylinder 3| is a returncylinder 35, in which is slidably mounted a vertically movable plunger36; The upper end of the plunger 36 is provided with .a'- cross-head 31which (is rigidly-uconnectedto a cross-head38 on the lower end. oftheplunger38 by a pair of tie rods 39,39.

The cylinder 35 is connected to a constant source of uniform pneumaticpressure, by a conduit 48, which at all times admits fluid underpressure to the lower end of the plunger 36;within-cylinder'35, andopposes the downward movement of the plungerfill by fluid pressureadmitted to thelcylinder 3| through the conduit 34.

As soon as the-mandrel I8 has moved the forging B through the throat ofthe roll pass formed by the rolls R R and when the transverse plane z2!of the forging substantially coincideswith the plane XX of the bite ofthe rolls R R the fluid supply to the cylinder 3| through the conduit 34is manually or automatically cut off and permitted to exhaust by thereverse movement through the conduit 34, whereupon, the constant-uniformpressure entering the lower end of the cylinder 35 through the conduit48 returns the plunger 30 to its upper or normal inactive position shownin Fig. .3.

Further advancing movement of the forging 12. by the mandrel m slidesthe ram in its guideways 23a23b until the rear end IQ of saidram-engages a resilient buffer 4|, which brakes the accelerated forwardmovement of the forge ing B which takes place whenthe rear end 12 of theforging B leaves the bite of the rolls R R The buffer head 4| isprovided with a stem 42 which is slidably mounted in a cross member 43located at the rear end of the guideway 2311-23?) for the ram 20. Therear end of said stem 42 is-slidably. mounted in a buffer plate 44. Thestem'42 of the buffer 4| is provided with an adjustable flanged nut45between which and the buffer plate 44 is mounted the buffer spring 46.

The anvil I5- is projected through the throat of the pass formed by therolls R R and into the throat of the pass formed by the rolls R ,.Rinthe-present instance, by one or the other of a pair of dogs 41, 41which are carried by an endless chain 48. Therear face I9 of the ram 28isprovided with a recess 43 into which one of the dogs 4! enters andslides the ram 25 and anvil 15 along the guideway 2311-2319, in thedirection of the arrow 03, until the roller 25 on the bell crank lever26, which,.during said sliding of the ram 20 travelsalong the top of theram 28, rides down and against the rear end l9 of the ram.

Thechain 48 at the uprights 28,28, is seated in acircumferential groove58 formed inthe face ofa roller 5|, which is rotatably mounted, betweensaid uprights, on a shaft 52 having its opposite ends journaled in abearing formed in or carried by a pair of brackets 56, 56 secured to theuprights 28, 28.

Between the grooved wheel 5| and the rear end of the guideway 23a23b forthe ram 20, the chain 48 rides in a circumferential groove 53 formed inasecond wheel 54 which is rotatably mounted on a shaft 55 having itsopposite ends journaled in or carried by said pair of brackets 56, 56which are secured to the uprights 28,28.

The outer peripheral surfaces of the grooved wheels. 5| and 54 serve tosupport the rear end of the cross-head22 which is projected beyond therear end of the cross-head guide 23a when the cylindrical end 2| andanvil l5 of the ram 20. are projected into and through the throat formedby the rolls R R The uprights 28, 28 are spaced from andrigidlyisecuredtotheframe 6, which houses=the pass rolls R R ,'by.2 apair .of upper laterally spaced stringers 5'5, 51, and by a lowerstringer bolt 58. The rear end of the bolt 58 is anchored in a spacingmember 59 supported by and between the uprightsZS, 28 and to which saidspacing member is secured by a series of bolts or rivets 60, 60.over-hanging end of the base 32 of the cylinder 3| is supported by meansof angular braces 6|, 6| which are secured at their one end to theuprights 28 by bolts 62, 62, and at their opposite end to the base 32 bybolts or rivets 63, 63. a

The buffer block 43 is supported by a pair of laterally spaced uprights6 3, 64. The uprights 64, 64 are secured to and spaced from theuprights28, 28 by a pair .of upper horizontally extending tie bolts 66 and apair of lower horizontally-extending tie bolts 61, 6'5. The buffer plateplate A l is secured to the rear sides of the uprights 64 by the tierods 66, 66 and 61, 61.

The upper. guideway 23b, for the ram 28, is provided with transverselyextending arms 68, 68 which are mounted on the tie bolts 66, 66 and thelower guideway 23a is provided with a pair of transversely extendingarms 66, 69 which are supported by the lower tie bolts 67!, 6'l. Thelower guideway 23a. is provided with a longitudinal groove 16, in whichthe chain 46 travels beneath the ram 26. 1

The end of the chain 48 adjacent the uprights 64, 64, passes around asprocket 70 whic is secured to a transverse shaft Ii, intermediate apair of brackets 12, ;l2, which are respectively secured to the uprights65, 6*: by bolts 73, 13. The shaft 7! is rotatably mounted in thebrackets 12 and is. provided with a hand wheel 15, by which the chain 48may be operated to move the ram 26 and anvil I5 in the direction of thearrow (2?, and into position to backup a forging advanced into the biteof the rolls R R by the mandrel I0.

As shown in Fig. 4, the bell crank lever 26 is formed of three rigidlyconnected parts including a pair of outside members 26a, 26a, and anintermediate member 261), with all three parts rigidly secured togetherby rivets etc. The intermediate member 2611 is provided with recesses Tland 18 in which the rollers and 29, respectively, rotate.

'The lower end of the plunger 36 is provided with an interchangeableinsert 19 against which the roller 29 of the bell crank lever 26 rides,for replacement in case of excessive wear resulting from the heavypressure transmitted thereby.

The cylindrical section 2i and anvil l5 are. interchangeably mounted inthe ram 26 for changing in accordance with changes in the diameters ofthe forging being worked by the apparatus and corresponding variationsin the diameters of the throats of the passes R R and R R While theshape of the bottom of the cavityC has herein been described as beingparabolic and the shape of the nose of the mandrel l0 has herein beendescribed as being paraboloidal, it will be understood that the bottomof the cavity and the nose of the mandrel may be of a frustoconical ortapering shape without departing from The to receive any of the wellknown explosives com monly employed in high explosive shells.

I claim: a

1. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, means engageable with the exterior bottomsurface of the forging for resiliently opposing initial axial movementof the forging through said pass by said mandrel, and means forrendering said opposing means ineffective after said mandrel hasadvanced said forging a distance less than'the full length of theforging through said pass.

2. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, means including an anvil engageable withthe exterior bottom surface of the forging for resiliently opposinginitial axial movement of the forging through said pass by said mandrel,and means for rendering said opposing means ineffective after saidmandrel has advanced said forging a distance less than the full lengthof the forging through said pass.

3. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, an anvil engageable with the exteriorbottom surface of the forging, means for applying a predetermined forceto said anvil for resiliently opposing initial axial movement of theforging through said pass by said mandrel, and means for rendering saidopposing means ineffective after said mandrel has advanced said forginga distance less than the full length of the forging through said pass.

4. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, an anvil engageable with the exteriorbottom surface of the forging, a ram axially aligned with said mandreland supporting said anvil, means for applying a predetermined force tosaid ram for resiliently opposing initial axial movement of the forgingthrough said pass bysaid mandrel, and means for rendering said opposingmeans ineffective after said mandrel has advanced said forging adistance less than the full length of the forging through said pass.

5. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface ofa hollow forging to force the forgingcompletely through said pass, an anvil engageable with the exteriorbottom surface of the forging, a ram axially aligned with said mandreland supporting said anvil, means for applying a predetermined force tosaid ram including a plunger operable in one direction in a cylinderunder fluid pressure for resiliently opposing initial axial movement ofthe forging through said pass by said mandrel, and means for renderingsaid opposing means ineffective after said mandrel has advanced saidforging a distance less than the full length of the forging through saidpass.

6. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, an anvil engageable with the exteriorbottom surface of the forging, a ram axially aligned with said mandreland supporting said anvil, means for applying a predetermined force tosaid ram including a plunger disposed at an angle to the axis of saidram and operable in one direction in a cylinder under fluid pressure,and a bell crank lever operable between said plunger and said ram forresiliently opposing initial axial movement of the forging through saidpass by said mandrel.

7. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, an anvil engageable with the exteriorbottom surface of the forging, a ram axially aligned with said mandreland supporting said anvil, means for applying a predetermined force tosaid ram including a plunger operable in one direction in a cylinderunder fluid pressure for resiliently opposing initial axial movement ofthe forging through said pass by said mandrel, and means for renderingsaid opposing means ineffective after said mandrel has advanced saidforging a distance less than the full length of the forging through saidpass, and means constantly opposing said movement of said plunger insaid one direction resiliently for moving said plunger reversely upondiscontinuance of said fluid pressure to said cylinder.

8. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forgingcompletely through said pass, an anvil engageable with the exteriorbottom surface of the forging, a ram axially aligned with said mandreland supporting said anvil, means for moving said ram in one direction toapply a predetermined force to said ram for resiliently opposing initialaxial movement of the forging through said pass by said mandrel, andmeans for rendering said opposing means ineffective after said mandrelhas advanced said forging a distance less than the full length of theforging through said pass, and a buffer engageable by said ram to checkmovement thereof in the opposite direction when said force is released.

9. A forging apparatus, comprising a pass, a mandrel engageable with theinterior bottom surface of a hollow forging to force the forging throughsaid pass, an anvil engageable with the exterior bottom surface of theforging, a ram axially aligned with said mandrel and supporting saidanvil, means including a bell crank lever pivoted adjacent the path ofmovement of said ram and having one arm engageable with a transverselyextending face of said ram for applying a predetermined force to saidram for resiliently opposing initial axial movement of the forgingthrough said pass by said mandrel, said arm being movable out of thepath of said ram upon predetermined partial movement of said forgingthrough said pass by said mandrel and means for moving said ram intoposition for engagement by said bell crank and said forging prior to theapplication of said of said force to said ram.

10. A forging apparatus, comprising a pass, a guideway beyond one end ofsaid pass, a mandrel engageable with the interior bottom surface of ahollow forging to force the forging completely through said pass, a ramaxially aligned with said mandrel and engageable with the exteriorbottom surface of the forging for resiliently opposing initial axialmovement of the forging through said pass by said mandrel, said ramincluding a cross-head slidably mounted in said guideway, and acylindrical portion movable into said pass to engage said exterior endof said forging.

11. A forging apparatus, comprising a pass, a horizontal guideway beyondone end of said pass, a horizontal mandrel engageable with the interiorbottom surface of a hollow forging to force the forging completelythrough said pass, a ram slidably mounted in said guideway in axialalignment with said mandrel and engageable with the exterior bottomsurface of the forging, a vertically movable plunger operable in onedirection in a vertically disposed cylinder under fluid pressure, and abell crank lever having one arm engageable by said plunger and a secondarm engageable with said ram for resiliently opposing initial axialmovement of the forging through said pass by said mandrel.

12. A forging apparatus, comprising a horizontal pass, a horizontalguideway, a horizontally movable mandrel engageable with the interiorbottom surface of a hollow forging to force the forging completelythrough said pass, a horizontally movable ram slidably mounted in saidguideway in axial alignment with said mandrel and engageable with theexterior bottom surface of the forging, and means for applying apredetermined force to said ram, including a vertically operable plungeroperable in one direction in a vertically disposed cylinder under fluidpressure, and a bell crank lever transmitting said force from saidplunger to said ram for resiliently opposing initial axial movement ofthe forging through said pass by said mandrel.

13. A forging apparatus, comprising a horizontal pass, a horizontalguideway, a horizontally movable mandrel engageable with the interiorbottom surface of a hollow forging to force the forging through saidpass, a horizontally movable ram slidably mounted in said guideway inaxial alignment with said mandrel and engageable with the exteriorbottom surface of the forging, and means for applying a predeterminedforce to said ram, including a vertically operable plunger operable inone direction in a vertically disposed cylinder under fluid pressure, abell crank lever transmitting said force from said plunger to said ramfor resiliently opposing initial axial movement of the forging throughsaid pass by said mandrel, a constant pressure cylinder superposed onand axially aligned with said vertically disposed cylinder, a plungeroperable in said superposed cylinder in opposition to said verticallyoperable cylinder, a cross-head on each plunger, and tie rods operablyconnecting said cross-heads outside said cylinders.

14. The method which comprises inserting a shaping mandrel in a cavityof a hollow forging for engagement with the interior bottom surface ofthe hollow forging, applying a predetermined force to said mandrel forpushing said forging in one axial direction through the throat of areducing pass, and applying a lesser counterdirectional force to theexterior bottom surface of said forging for resiliently opposing initialaxial movement of the forging through said pass by said mandrel toinsure full surface engagement between said mandrel and the surroundingwall of said cavity and discontinuing said counter-directional forceafter a predetermined partial movement of the forging through said passhas been effected.

LE ROY LAYTON.

